Art of manufacturing rubber footwear.



W. E. PIPER.

ART OF MANUFACTURING RUBBER FOOTWEAR.

APPLICATION FILED MAR. I9. 19m.

Llfifififig. v Patented Oct.26,1915.

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ART OF MANUFACTURING RUBBER FOOTWEAR.

To all whom it may concern:

Be it known that T, WALTER E. PIPER, a citizen of the United States, and resident of Melrose, in the county of Middlesex and State of Massachusetts, have invented an Improvement inthe Art of. Manufacturing- Rubber Footwear, of which the following description, in oonhection with the accompanying drawings, is a specification, like letters on the drawings representing like Parts.

My invention relates to the process of manufacturing rubber footwear, and its object is to aflord an improved process and to perfect the product I In the "manufacture of rubber footwear as now ordinarily carried out in large factories, it is customary to assemble the lining, upper, reinforcing pieces, and sole successively. upon a lastby hand, and, in order properly .toconformthese various parts of the shoe to the last a number of hand operations are necessary. The insole and lining, having been first stamped'out and applied by hand .to a last, are subjected to a rolling operation, in order to conform them, at theedge of'the sole where the lining overlaps the insole, to the irregularrontour of the last on which they arepositioned. This rolling is accomplishedby a' han'd operation, the

operator using a small rsteeljcylindrical roll having a straight-surface and endeavoring to make the lining 'fit sm'oothly and evenly, Without wrinkles or any unevennesses, by

manipulating the straight surface of the roller over the contour of the last'and thus lasting the lining thereon. Then the reinforcing pieces, if any,-.such as counter,

pipings .or'strips around the edge portion, toe-cap. etc. are applie d by hand, and each 7 is successively rolled to make it fit and conform smoothly in'its'respective position.

Ttwill be understood that in making rub- .ber footwear, the various layers constituting the. shoe or overshoe are prepared from plastic and sticky stock which, together with the outer rubber coating and the subsequent vulcanizing operation, constitute the sole -means of holding the various layers together, no sewing or other processes being usually required. Therefore, the various successive hand rolling operations just described are of great importance, not only in smoothing and conforming the layers to the shape'of the last on which they are assemticle.

mately connected and stuck together in asubstantially homogeneous article. Consid- Specification of Letters Patent. Pm'tagmtg gd M g-fig, 26, 119115, Application filed March 19, 1913. Serial No. 755,416. I

erable pressure is therefore necessary in the rolling operation to insure satisfactory results. With the lining and other layers thus prepared, the'rubber upper is then applied and it is similarly rolled .by hand and the lower edges of the upper are turned over? and folded or crimped'onto the innersole,

the outsole then being applied and also rolled. A still further rolling operation is required in the ordinary process which is of great importance and consists in forcing the edge portion of the .outsole, cut on a bevel for this purpose, over against the upper to make a firm and water-tight joint, which is afterward completed by the vulcanizing" process.

During the various hand operations of rolling, the various layers, including the rubber upper itself, are apt to be displaced, the rolling action naturally tending to-move, shove or cause an unsatisfactory product. Great difficulty has also been found heretofore in seeing that the operators rolled over every part of the surface, as such operators, ordinarily being employed on piece-work,

are anxious to turn out a large number of pairs, being more interested in quantity than quality, and therefore are liable to slight the very important rolling operations. It will also be seen that, by reason of these hand operations and the repeated and con tinual hand rolling, the hand labor required in present methods is unduly great for this ste of manufacturing. Furthermore, it-is di cult for .a. roller having a straight edge to make the layers conform suitably to the varying curved contours of a shoe last, and great skillis required in this hand rolling operation in order to secure a first-class ar- A still further objection is that an operator does not always perform this rolling work with the same degree of strength, and hence it is impossible to secure a uniformity of product under the method above outlined.

' My present process obviates entirely the objections and difiiculties above noted, and provides an automatic step in the process of making rubber footwear which accomplishes in one simple operation the same work heretofore done by the various hand rolling operations.

lllld An important feature in my process also is that the output of a uniform product is rendered possible, and that every part of the work is subjected to exactly the degree of pressure required, without any portion being slighted, and without any tendency to displace the various parts or to cause them to creep. My process also may be carried out by means of unskilled labor and with great economy of time, space, and expense. Furthermore, my method, by pro ducing a more firmly compressed and uniformly made shoe or rubber, especially at the joint between the upper and outsole, facilitates the solidifyingof the rubber in the subsequent vulcanizing process.

.In carrying out my improved process, I preferably subject the completely assembled shoe, overshoe or the like to pressure applied simultaneously throughout the entire contour of the upper and sole after the various layers have been assembled. By placing the last and assembled materials in a mold having flexible or yieldable diaphragms which automatically conform to the varying contour of the last when pressure is applied on the outside of said diaphragms, I am enabled to practise my process economically and expeditiously. Preferably twodiaphragms will be employed, one shaped roughly to fit the upper, and a lower diaphragm formed roughly to fit the sole or bottom portion of the shoe, and by applying fluid pressure, such as by any pneumatic or hydraulic means, to the ex terior of said diaphragms, the several layers comprising the rubber shoe are firmly, evenly, and simultaneously compacted into a substantially homogeneous article and' at a single operation. Any desired degree of pressure can be applied, and may be maintained for such length of time as will best suit the work being treated.

I have discovered that by applying pressure to the outer surface of the,series of layers of materials comprising the rubber shoe, while still upon the .last, and'by forcing out all the air contained either between the shoe materials and the last,.or impregnating the various layers, that I am enabled to produce a more firmly compacted and 'formed shoe, greatly increasing the cohesion of the, various layers and preparing the entire shoe in the best possible manner for the vulcanizing process. It is, therefore, an important feature of my present process, to allow or pro- .vide forthe escape of the air contained between the flexible diaphragms as they are forced into contact with the shoe upper materials during the application of fluid ressure on the outside of said diaphragms.

referably, therefore, the air is allowed to escape freely as it is forced out of the moldmg. apparatus by the continued inflation of the rubber diaphragms. When the air is thus substantially forced out, it will be readily appreciated that I amenabled to secure the advantages of the full amount of pressure exerted on'the shoe materials for the purpose of compacting the same, the pressure applied upon the outer surface of the diaphragms not being counteracted by any atmospheric pressure which was at first present, owing to the air contained between the diaphragms before they were forced into intimate contact about the shoe. I am aware that the vulcanization of rubber footwear has been accomplished under pressure, but I believe it to bea distinct novelty as a process of preparing rubber footwear for vulcanization, to exclude the air between the last and shoe materials as well as between the layers of such materials by the application of pressure upon the outer surface of the said materials. It will be readily appreciated that such atmospheric pressure amounting to approximately fifteen pounds per square inch is of very material extent. and by using a pressure of, -say, twenty pounds per square inch on the outer surfaces of the diaphragms to exclude the air, I am enabled to obtain the advantages of a greatly increased effect when the air has been actually excluded.

Suitable apparatus to carry out my improved method is shown in copending ap plications Serial Nos. 755,414, filed Mar. 19, 1913, and 786,318, filed August 23, 1913, and I will now explain the further carrying out of the process by means of the apparatus described and claimed in said copending upper member 2 pivoted at 3 on suitable lugs 4 formed on the lower member 1, and both being supported on a bench or the like 5. The lower member 1 has a bedor depression 6 formed therein at the right hand end,fviewing Fig. 2,-and the upper member has a dome 7 'formed thereon and adapted to cover and register with the depression 6 in the 'lower member when the upper member 2 is swung on the pivot-3 to contact with themember -1 in the position shown in Fig. 2. The pivotal connection 3 between the members 1 and 2 allows the upper member to be swung upward so that a .lasted .sh'oe may be placed by the operator meaeee periphery of the dome, and secured to this flange by means of a ring 9 of corresponding area'and contour to. the rim 8 by a plurality of set screws 10, is the edge portion of a yielding diaphragm 11. The diaphragm 11 is preferably of rubber and is formed roughly in the contour of a shoe upper projecting into the dome 7, as clearly illustrated in Figs. 1 and 2. The screws 10 are countersunk in the rim 9 wherever the same may be positioned, and are correspondingly tapped into the flang 8 of the dome 7 so that the outer surface of thering 9 presents a smooth surface. A corresponding diaphragm 12 of rubber or the like is secured to the rim 13 of the bed 6 by a ring 14 in a similar manner to that just described as holding the diaphragm 11 to the rim of the dome 7. This lower diaphragm 12 is formed in the outline of a shoe sole, having a transverse rib 15, which is substantially in position to fit the shoe shank or arch to be acted upon. The rings 9 and 14 are of equal area and contour and as the upper member 2 is lowered into the position shown in Fig. 2, the rim 9 of the dome is arrangedto rest upon the ring 14: and thus to supportthe dome in lowered position. Preferably, the

, members 1 and 2 may be locked together, in

any suitable way, or the Weight of the member 2 may be suflicient to hold it in contact with the lower member 1 during the operation of the apparatus. The dome 7 and the bed 6 are provided with ports lbeand 17 respectively to receive from any suitable source of power (not shown) the fluid pres- I sure, either pneumatic or hydraulic, being adaptable for use therein. 1 preferably employ a pneumatic pressure, but also contemplate the use of fluid pressure in the lower portion of. the mold contained. in the bed 6, and pneumatic pressurein the dome 7 Pressure being applied to the-dome and bed through the ports 16 and 17. respectively, the diaph-ragms 11 and 12 are correspondingly forced in a direction toward each other. If a. last 19 and its assembled shoe materials 20 are positioned within themold, it will be readily seen that the diaphragms 11 and 12 will fold about the last during the admission of pressure in the ports 16 and 17, the yielding nature ofthese diaphragms causing them to automatically conform to a wide range in size or style of last and shoe contained therein. This affords means for the application of pres sure throughout the entire extent of the rubber shoe. Any desired degree ofpressure may be supplied, and therefore the Various layers comprising the shoe 20 can be simultaneously forced into intimate and homogeneous contact, smoothing out all' wrinkles and taking the place 'of the former rolling operations already mentloned. By applying pressure simultaneously, the various layers comprising the shoe are not dis placed and are, in fact, more. firmly and densely compacted than by a mere rolling,

where the pressure is applied only momentarily during the passing of the roller. By my process 1 ,am enabled to apply and maintain any desired degree of pressure for any desired length of time until the shoe materials have set in a suitable manner. It is within the scope of my process to either provide hand controlled mechanism to supply, maintain and release the pressure sole are all applied to the last in theusual order and in the customary manner, but

without-the rolling operation, or with only suflicient hand rolling to hold the various layers in place. It will be readily understood by those skilled in the art, that the various materials or layers comprising rubher footwear instantly adhere when assem bled and therefore but little or no rolling is required to hold these materials in their respective positions. The operatorthen raises the upper member 2 and places the shoe with the upper materials thereon within the mold,

resting the same upon the lower diaphragm "12 and utilizing the rib 15 as a means to position the shoe longitudinally within the bed 6 and dome 7. The member '2'and dome 7 willlth en be lowered until thering 9 there of rests-upon the ring 14 of'the'bedb, when the same may be locked'together, if -.desired.

Pressure being now appliedthrough the respectively are expanded and automatically fit aboutthe shoe, as just explained, during the continuous application of pressure, until ports 16 and 17, ,the .diaphragms 11 and'12 f the desired degree of force is mai ntained within the mold. I. find',--that"some twenty to thirty pounds pressuretper square inch 'is productiveofjbest results iii-the manufacture of light weight, rubber oyershoes, al-' though of course" a greater'or' a lessdegree maybe found'best for different styles and gr'ades'of footwear, and the materials used therein. With twenty pounds pressure the rubber shoewill be ordinarily contained within the mold only momentarily, and the fit,

pressure may thenbe released and the dome I 7. lifted and the shoe removed, being then ready for the vulcanizing. process. The contacting surfaces of rings 9 and 14 are, of course, not airtight, and thus all the air contained between the diaphragms- 11' and- 12 and between the shoe materials 20 and last 19 will readily escape through the said contacting surfaces during the operations just described. Air is, of course, contained w1th1n any wrinkles or unevennesses between the various adj acentlayers, and between the layers as a whole and the last, and the preseasily, and the shoe just operated upon removed. I am thus enabledto secure a more uniform product than has ever been possible heretofore through the hand rolling operations and to effect the compacting. of the various layers in a much more satisfactory manner than heretofore. Also the danger of displacing the various layers or having them move or creep, as during hand.

rolling, is substantially eliminated Further'more, nopart of the surface of the shoe is-slighted or omitted and pressure is applied' evenly and uniformly to the entire shoe surface throughout the irregular contour of the last, irrespective of the style, or

model, in the manner bestisuited for the parts being-treated.

vI Flin'dlthat in"carrying out novel process,- as above described, the heretofore diflicultoggerationof'rolling the edge of the outer solefi'ipon andagainstthe upper is performed most advantageously, and automatically, 'a firm and tight 'join-t being insured at-this important-edge of the shoe, thus sole and u per most important portio s offth s e that [the diaphragm should" fit present than in "other part facilitating a.wat er-t ght oint between out-- Brefer'ably I so arrange the and 12 that the greatest elding',iiand therefore" a bettting willb'e secure diaphragms' elasticity and: ter and "closer-2' atfand aroundlthe; I

shanktof the shoe",-iiespeic ally-, it

and that. substantially Ia; greater.

accomplished by making H i '11 andj12 of greater elastici wat the points ;mentioned in any desired way, that herei'n shown being to make the diaphraginsof'less thickness at these points. I By having the diaphragms 1 1 and 12 0f a; considerable elasticity, I am abletooperate withthe same apparatus upon a "great range of different sizes, styles and shapes of foot wear, as the yielding diaphragms automg tically conform to such sizes, stylesand shapes of lasts without "being especially made for operating upon any, one size or form. Thus, in carrymg out my process, a chllds overshoe and a mans overshoe may be successively placed in the mold for "operation without any change in the diaphragms. The advanta'ges of my novel process will be apparent as the hand labor heretofore required in this step in the manufacture of rubber footwear is substantially eliminated, and a much better, more uniform and evenly compacted shoe is produced for the subsequent step of vulcanization. By having a duplex molding apparatus, one shoe can be left subjected to the desired pressure, while the operator is removing a prior shoe and replacing another, this being an economical method of operation and one which affords considerable practical advantages in the practice of my invention.

The process whereby rubber shoe materials are firmly compacted by applying pressure to the outer surfaces by means of a mold or the like, which pressure is applied simultaneously throughout the entire extent as a step in preparing'the rubber shoe for the vulcanizing process, is, so far as I am aware, a distinct noveltv in this art, and therefore I desire to claim the same broadly. Fur-.

thermore, the application of pressure through means which tends to also exclude the air between the outer layer and the last on which the'shoe materials are assembled thus securing the entire advantages of the whole amount of pressure applied to said outer surface for the purpose of compacting the various shoe layers, is also believed to be a distinct novelty.

My process consists in the application of pressure to: take the place of the hand rollingoperations heretofore required; to secure a more homogeneous and cohesive mass in the exact form and contour of the last by an .instantaneous operation; and to apply pressure 1n the manner described, as a step in v h Idiaiphragms" preparing the rubber footwear for vulcani- 5 zation, and these features I wish to claim d at:the v Having described my invention, what I 1 claim as new and desire to secure by Let- 'tersjPatent is:

broadly.

1; Theimp1ovement in the art of manufacturing rubber shoes which consists in assembling to lightly adhere to each other upon alast the several layers that comprise .a completed shoe ready for vulcanization,

and then applying compacting pressure simultaneously to the entire exposed outer surface of the-completed shoe upon the last.

2.-The improvement in the art of manu-- facturing-rubber shoes which consists in assembling to lightly adhere to each other upon a last the several layers that comprise a completed shoe ready for vulcanization,

and-theni applyingcompacting pressure simultaneously and substantially of uniform amountto the entire exposed outer surface of the completed shoe upon the last.

3. The improvement in the art of manufacturing rubber shoes which consists in assembling to lightly adhere to each other upona last the several layers that comprise mtaaet w a completed shoe ready for vulcanization,

and then applying compacting pressure to the entire .e'lxposed outer surface of the completed shoe upon the last by means of a flexit ble medium arranged to conform automatically to the contour of said completed shoe.

4:. The improvement in the art ofmanufacturing rubber shoes which consists in assembling to lightly adhere to each other 10 upon a last the several layers that comprise a completed shoe ready for vulcanization, and then applying compacting pressure to the entire exposed, outer surface of the completed shoe upon the last by means of a '15 yielding medium of predetermined varying flexibility.

5. The improvement in the art of manufacturing rubber shoes which consists in assembling to lightly adhere to each other 0 cupon a last the several layers that comprise a completed shoe'ready for vulcanization,

then applying compacting pressure simultaneously to the entire exposed outer sur-.

face of the completed shoe upon the last, and simultaneously permitting the en- 25 trapped air contained within said completed shoe to-escape. i

6. That improvement in the art of manufacturing rubber shoes which consists in assembling the layers of materials constitut- 80 ing the shoe, comprising the inner sole, lining, counter, piping, upper and outer sole, upon a last without rolling said layers separately and subjecting them to pressure applied to the outer surface of the outer lay- 35 ers sufficient to compact the layers into the completed shoe ready for the subsequent vulcanizing process. 4

In testimony whereof, I havesigned my name to this specification, in the presenceof 40 two subscribing witnesses.

WALTER E. PIPER. Witnesses I Y GEO. H. MAXWELL,

JAMES R. HODbEB. 

